We propose a novel, high performance, and standalone system for improving close air support (CAS) effectiveness. First, we propose a standalone noise cancellation device (NCD) that can be inserted between the handset and the transceiver. As a result, there is no change to the existing communication system. The NCD is self-powered from its own battery and equipped with a microphone and a digital signal processing (DSP) chip to process the signals from the handset mic and the mic in the NCD. Second, in the NCD, we propose to apply blind source separation (BSS) algorithms to untangle speech from background noises. One BSS method is the Independent Component Analysis (ICA) and another method is known as Adaptive Decorrelation Filter (ADF). Our team has applied both ICA and ADF to various applications. Third, since there may still be residual noise after the BSS stage, we propose to apply a fast convergence adaptive filter to further eliminate the residual background noise. The particular adaptive filter was developed by this team some time ago and can at least double the speed of convergence as compared to a conventional adaptive scheme. The proposed algorithms will be implemented in DSP in Phase 2.